Electroporation shield for implantable electrodes

The present invention relates generally to electroporation with implantable medical devices, and, more specifically, to electroporation shields for electrodes of implantable medical devices.

Medical devices have provided a wide range of therapeutic benefits to recipients over recent decades. Medical devices can include internal or implantable components/devices, external or wearable components/devices, or combinations thereof (e.g., a device having an external component communicating with an implantable component). Medical devices, such as traditional hearing aids, partially or fully-implantable hearing prostheses (e.g., bone conduction devices, mechanical stimulators, cochlear implants, etc.), pacemakers, defibrillators, functional electrical stimulation devices, and other medical devices, have been successful in performing lifesaving and/or lifestyle enhancement functions and/or recipient monitoring for a number of years.

The types of medical devices and the ranges of functions performed thereby have increased over the years. For example, many medical devices, sometimes referred to as “implantable medical devices,” now often include one or more instruments, apparatus, sensors, processors, controllers or other functional mechanical or electrical components that are permanently or temporarily implanted in a recipient. These functional devices are typically used to diagnose, prevent, monitor, treat, or manage a disease/injury or symptom thereof, or to investigate, replace or modify the anatomy or a physiological process. Many of these functional devices utilize power and/or data received from external devices that are part of, or operate in conjunction with, implantable components.

In one aspect, a method is provided. The method comprises: positioning an electroporation-shielded stimulation arrangement of an implantable medical device proximate to cells of a recipient of the implantable medical device; applying an electroporation electrical field to the cells of the recipient using one or more electroporation electrodes of the electroporation-shielded stimulation arrangement; and exposing, in-situ, one or more stimulation electrodes of the electroporation-shielded stimulation arrangement.

In another aspect, a method is provided. The method comprises: providing an electroporation-shielded stimulation arrangement comprising one or more stimulation electrodes disposed in a carrier member and electrically connected to a stimulator unit of an implantable medical device, one or more electroporation electrodes electrically connected to an electroporation device, and an electroporation shield covering the one or more stimulation electrodes to electrically isolate the one or more stimulation electrodes from the one or more electroporation electrodes; positioning the electroporation-shielded stimulation arrangement proximate to cells of a recipient of the implantable medical device; applying an electroporation electrical field to the cells of the recipient using at least one of the one or more electroporation electrodes; and removing the electroporation shield from proximity to the cells of the recipient to expose the one or more stimulation that were covered by the electroporation shield to the cells of the recipient.

In another aspect, an apparatus is provided. The apparatus comprises: a stimulating assembly of an implantable medical device comprising one or more stimulation electrodes disposed in a carrier member, wherein the stimulating assembly is configured for implantation into a spatial region in a body of a recipient of the implantable medical device; an electroporation shield disposed over the plurality of stimulation electrodes, wherein the electroporation shield has an inner surface abutting the stimulating assembly and the plurality of stimulation electrodes, and an opposite outer surface; and one or more electroporation electrodes coupled to the outer surface of the electroporation shield.

In yet another aspect, an apparatus is provided. The apparatus comprises: a tissue-stimulating prosthesis comprising a stimulating assembly and a plurality of stimulation electrodes disposed on the stimulating assembly, the stimulating assembly being configured to be positioned in a recipient of the tissue-stimulating prosthesis proximate to cells of the recipient; and an electroporation shield removably coupled to the stimulating assembly and disposed over at least one of the plurality of stimulation electrodes of the stimulating assembly, wherein the electroporation shield is configured to electrically insulate the at least one of the plurality of stimulation electrodes from voltages equal to and greater than approximately 100 volts.

In another aspect, an apparatus is provided. The apparatus comprises: a tissue-stimulating prosthesis comprising a stimulating assembly and a plurality of stimulation electrodes disposed on the stimulating assembly, the stimulating assembly being configured to be positioned in a recipient of the tissue-stimulating prosthesis proximate to cells of the recipient; and an electroporation shield removably coupled to the stimulating assembly and disposed over at least one of the plurality of stimulation electrodes of the stimulating assembly, wherein the electroporation shield has a thickness of approximately 5 μm to approximately 100 μm, is constructed from silicone or polyurethane, is configured to electrically insulate the at least one of the plurality of stimulation electrodes from voltages equal to and greater than approximately 100 volts, and wherein the electroporation shield has a proximal end and a distal end, and at least one pull tab disposed proximate to the proximal end configured to facilitate removal of the electroporation shield by pulling the electroporation shield along the stimulating assembly of the tissue-stimulating prosthesis and out of proximity to the cells of the recipient.

Electroporation refers to the application of an electrical field to a cell (e.g., a mesenchymal stem cell) in a manner that creates an electrical potential (i.e., voltage difference) across the cell that, in turn, opens up pores in the membrane of the cell. The electrically opened pores may be used to, for example, allow a treatment substance to enter the cell through the cell membrane (i.e., as the potential difference is applied to the cell, the electrically opened pores in the cell membrane allow material to flow into the cell). After the electrical potential is removed, the pores in the cell membrane close such that the treatment substance remains in the cell. As such, electroporation may be useful with medical devices by altering the biological composition of the cells in a manner that enhances, enables, etc. operation of the medical device.

Successful electroporation requires a cell to be exposed to a large electrical field for a sufficient amount of time so that a desired treatment substance is able to migrate through the cell membrane. Such an electric field, sometimes referred to herein as an “electroporation electrical field,” utilizes a high voltage in the range of, for example, approximately 100 Volts (V) to approximately 150 V, over the distance between two or more implanted electrodes positioned in proximity to the target cells (i.e., the cells that are to be electroporated). Such a voltage range is considered “high” because such voltages exceed the typical operating range for electrical components of conventional implantable medical devices. That is, conventional implantable medical devices typically cannot be exposed to such voltages (without incurring damage) and, as a result, electroporation is generally performed using separate devices prior to implantation of an implantable medical device into a recipient.

Presented herein are techniques that enable electroporation of the cells of a recipient of an implantable medical device comprising electrode contacts (electrodes), referred to herein as “a tissue-stimulating prosthesis,” while the tissue-stimulating prosthesis is implanted in the recipient. More specifically, tissue-stimulating prostheses in accordance with embodiments presented herein are configured/arranged such that the stimulation electronics (e.g., current sources and integrated circuit) of the prosthesis are insulated from the high voltages used in electroporation. In certain embodiments, an “electrical electroporation shield” or “electroporation shield” is disposed between the stimulation electronics and the implanted electroporation electrodes while the electroporation electrodes generate an electroporation electrical field. The electroporation shield is configured to protect the stimulation electronics from damage (e.g., from the high voltages) during the electroporation.

As noted, there are several types of tissue-stimulating prostheses that deliver stimulation signals (current signals) to compensate for a deficiency in a recipient. Merely for ease of illustration, the embodiments presented herein are primarily described herein with reference to one type of tissue-stimulating prosthesis, namely a cochlear implant. However, it is to be appreciated that the techniques presented herein may be used with other tissue-stimulating prostheses and/or other implantable medical devices, including, for example, other auditory prostheses such as middle ear auditory prostheses (middle ear implants), bone conduction devices, direct acoustic stimulators, electro-acoustic prostheses, auditory brain stimulators, etc. The techniques presented herein may also be used with systems that comprise or include, for example, tinnitus therapy devices, vestibular devices (e.g., vestibular implants), sensors, drug delivery systems, defibrillators, implantable pacemakers, functional electrical stimulation devices, catheters, seizure devices (e.g., devices for monitoring and/or treating epileptic events), sleep apnea devices, spinal cord stimulators, deep brain stimulators, motor cortex stimulators, sacral nerve stimulators, pudendal nerve stimulators, vagus/vagal nerve stimulators, trigeminal nerve stimulators, retinal or other visual prosthesis/stimulators, occipital cortex implants, diaphragm (phrenic) pacers, pain relief stimulators, other neural or neuromuscular stimulators, etc.

is a schematic diagram of an exemplary cochlear implant systemconfigured to implement aspects of the techniques presented herein, whileis a block diagram of the cochlear implant system. For ease of illustration,will be described together.

The cochlear implant systemcomprises an external componentand an internal/implantable component, which is sometimes referred to herein as “cochlear implant”. The external componentis directly or indirectly attached to the body of the recipient and typically comprises an external coiland, generally, a magnet (not shown in) fixed relative to the external coil. The external componentalso comprises one or more input elements/devicesfor receiving input signals at a sound processing unit. In this example, the one or more input devicesinclude sound input devices(e.g., microphones positioned by auricleof the recipient, telecoils, etc.) configured to capture/receive input signals, one or more auxiliary input devices(e.g., audio ports, such as a Direct Audio Input (DAI), data ports, such as a Universal Serial Bus (USB) port, cable port, etc.), and a wireless transmitter/receiver (transceiver), each located in, on, or near the sound processing unit.

The sound processing unitalso includes, for example, at least one battery, a radio-frequency (RF) transceiver, and a processing module. The processing modulemay comprise a number of elements, including a sound processor.

In the examples of, the sound processing unitis a behind-the-ear (BTE) sound processing unit configured to be attached to, and worn adjacent to, the recipient's ear. However, it is to be appreciated that embodiments of the present invention may be implemented by sound processing units having other arrangements, such as by an off-the-ear (OTE) sound processing unit (i.e., a component having a generally cylindrical shape and which is configured to be magnetically coupled to the recipient's head, etc.), a mini or micro-BTE unit, an in-the-canal unit that is configured to be located in the recipient's ear canal, a body-worn sound processing unit, etc.

Returning to the example embodiment of, the implantable component (cochlear implant)comprises an implant body (main module), a lead region, and an intra-cochlear stimulating assembly, all configured to be implanted under the skin/tissue (tissue)of the recipient. The implant bodygenerally comprises a hermetically-sealed housingin which RF interface circuitryand a stimulator unitare disposed. As described further below, the stimulator unitcomprises stimulation electronics. The stimulation electronicscomprises, among other elements, one or more current sources on an integrated circuit (IC). The implant bodyalso includes an internal/implantable coilthat is generally external to the housing, but which is connected to the RF interface circuitryvia a hermetic feedthrough (not shown in).

As noted, stimulating assemblyis configured to be at least partially implanted in the recipient's cochlea. Stimulating assemblyincludes a carrier memberand a plurality of longitudinally spaced intra-cochlear electrodesdisposed in/on the carrier member. The intra-cochlear electrodescollectively form a contact or electrode arrayconfigured to deliver electrical stimulation signals (current signals) to the recipient's cochlea and/or to sink stimulation signals from the recipient's cochlea.illustrates a specific arrangement in which stimulating assemblycomprises twenty-two (22) intra-cochlear electrodes, labeled as electrodes() through(). It is to be appreciated that embodiments presented herein may be implemented in alternative arrangements having different numbers of intra-cochlear electrodes.

Stimulating assemblyextends through an opening in the recipient's cochlea (e.g., cochleostomy, the round window, etc.) and has a proximal end connected to stimulator unitvia lead regionand a hermetic feedthrough (not shown in). Lead regionincludes a plurality of conductors (wires) that electrically connect the electrodesto the stimulator unit.

Also shown inis an extra-cochlear electrode(). The extra-cochlear electrode() is an electrode contact that is configured to, for example, deliver electrical stimulation to the recipient's cochlea and/or to sink current from the recipient's cochlea. The extra-cochlear electrode() is connected to a reference leadthat includes one or more conductors that electrically couple the extra-cochlear electrode() to the stimulator unit.

As noted, the intra-cochlear electrodes()-() and the extra-cochlear electrode() can be used post-operatively to stimulate the cochleaof the recipient (i.e., operate as delivery or return paths for current signals to the cochlea) that evoke a hearing perception. As such, for ease of description, the intra-cochlear electrodes()-() and the extra-cochlear electrode() are sometimes collectively and generally referred to herein as “stimulation electrodes.”

also illustrate that the stimulating assemblyincludes two (2) electroporation electrode contacts (electrodes)() and(). As described further below, the electroporation electrodes() and() are electrically connected to an external electroporation system/device(shown in) via an electroporation lead(e.g., one or more wires). As described elsewhere herein, the electroporation electrodes() and() can be used to electroporate the recipient's cochlea nerve cells during implantation of the stimulating assemblyinto the cochlea. That is, the electroporation electrodes() and() may be configured to source, sink, or both source and sink electroporation signals (generated by external electroporation device) that result in the application of an electroporation electrical field to the nerve cells of the cochlea. Thereafter, the electroporation electrodes() and() can be electrically isolated from the external electroporation device(e.g., electrically disconnected). Although shown as two electrodes located at the distal endof the stimulating assembly, more than two electroporation electrodes may be present and used for electroporation.

As noted elsewhere herein, electrodes configured for use in performing electroporation, such as electrodes() and(), are referred to as “electroporation electrodes.” The electroporation electrodes()/(), and the external electroporation device, are collectively referred to herein as an “electroporation sub-system”. In the embodiments of, the electroporation systemis referred to as being integrated with the cochlear implant system.

Electroporation electrodes() and() are structurally distinguishable from the stimulation electrodes()-() in that the electroporation electrodes are not connected to the stimulator unit, whereas the stimulation electrodes()-() must be connected to the stimulator unitto enable operation thereof. In particular, the high voltages associated with electroporation could damage the stimulator unitand, as such, the stimulation electrodes()-() cannot be used to perform electroporation. In addition, in order to perform electroporation while the stimulation electrodes()-() are implanted, the electroporation electrodes() and() must be electrically isolated from the stimulator unit. Presented herein are techniques to electrically isolate the stimulator unitfrom the electroporation electrodes() and(), and thus the high voltage electroporation signals, with an electroporation shield.

Electroporation may have a number of associated purposes. In certain examples, the electroporation is used to open the pores in the cells in the presence of a treatment material (therapeutic agent) in order to enable an effective amount of the therapeutic agent to enter the electroporated (opened) cells. As used herein, the term “therapeutic agent” or “treatment material” may include, but is not limited to, biological or bioactive substances, chemicals, pharmaceutical agents, nanoparticles, ions, including nucleic acids (e.g., Deoxyribonucleic acid (DNA), DNA cassettes, cDNA, or plasmids, Ribonucleic acid (RNA) molecules, RNAi, etc.), proteins, peptides (e.g., Brain-derived neurotrophic factors, etc.), hormones, etc. Therefore, in accordance with certain embodiments, prior to electroporation, a therapeutic agent may first be delivered to the cochlea. Such a therapeutic agent may be delivered in a number of different manners, such as through an implantation tool, substance delivery device (e.g., lumen, syringe, etc.), a coating on the stimulating assembly, etc.

As noted, the cochlear implant systemincludes the external coiland the implantable coil. The coilsandare typically wire antenna coils each comprised of multiple turns of electrically insulated single-strand or multi-strand platinum or gold wire. Generally, a magnet is fixed relative to each of the external coiland the implantable coil. The magnets fixed relative to the external coiland the implantable coilfacilitate the operational alignment of the external coil with the implantable coil. This operational alignment of the coilsandenables the external componentto transmit data, as well as possibly power, to the implantable componentvia a closely-coupled wireless link formed between the external coilwith the implantable coil. In certain examples, the closely-coupled wireless link is a radio frequency (RF) link. However, various other types of energy transfer, such as infrared (IR), electromagnetic, capacitive and inductive transfer, may be used to transfer the power and/or data from an external component to an implantable component and, as such,illustrates only one example arrangement.

As noted above, sound processing unitincludes the processing module. The processing moduleis configured to convert input audio signals into stimulation control signalsfor use in stimulating a first ear of a recipient (i.e., the processing moduleis configured to perform sound processing on input audio signals received at the sound processing unit). Stated differently, the sound processor(e.g., one or more processing elements implementing firmware, software, etc.) is configured to convert the captured input audio signals into stimulation control signalsthat represent stimulation signals for delivery to the recipient. The input audio signals that are processed and converted into stimulation control signals may be audio signals received via the sound input devices, signals received via the auxiliary input devices, and/or signals received via the wireless transceiver.

In the embodiment of, the stimulation control signalsare provided to the RF transceiver, which transcutaneously transfers the stimulation control signals(e.g., in an encoded manner) to the implantable componentvia external coiland implantable coil. That is, the stimulation control signalsare received at the RF interface circuitryvia implantable coiland provided to the stimulator unit. The stimulator unitis configured to utilize the stimulation control signalsto generate stimulation signals (e.g., current signals) for delivery to the recipient's cochlea via one or more stimulation electrodes()-(). In this way, cochlear implant systemelectrically stimulates the recipient's auditory nerve cells, bypassing absent or defective hair cells that normally transduce acoustic vibrations into neural activity, in a manner that causes the recipient to perceive one or more components of the input audio signals.

As noted, electroporation refers to the application of an electrical field to a cell such that pores are opened in the cell membrane. When these cells are opened in the presence of a treatment substances, such as neural growth factor genes, the treatment substances may enter the cell through the cell membrane. After the electrical potential is removed, the pores in the cell membrane close such that the treatment substances remains in the cell.

Also as noted, successful electroporation requires a cell to be exposed to a large electrical field utilizing a voltage that is sufficiently high, such as a voltage in the range of approximately 100 Volts (V) to approximately 150 V, which may damage conventional cochlear implants, namely the stimulation electronics. For this reason, conventional techniques generally rely on the use of a dedicated electroporation array that is temporarily inserted into a spatial region within the body of a recipient (e.g., a cochlea) during surgery. This dedicated electroporation array is used to perform the electroporation procedure and then removed from the cochlea, after which a normal intra-cochlear stimulating array is inserted. Insertion of electrode arrays into the delicate cochlea is always a risk to the recipient, and it is therefore desirable to have only one insertion procedure during surgery. As such, presented herein are techniques that enable electroporation of the cochlea nerve cells while the cochlear implant is implanted in the recipient by isolating the stimulation electronics from the high voltages used during the electroporation.

More specifically, in the example of, the electroporation electrodes() and() are used to electroporate the recipient's cochlea nerve cells during implantation of the stimulating assemblyinto the cochlea(i.e., used during application of an electroporation electrical field to the cochlea). As further described herein, the stimulating assemblymay also be equipped with an electroporation shield that serves to electrically insulate (e.g., electrically isolate or shield) the intra-cochlear electrodes()-(), and thus the stimulator unit, from the electroporation electrical field applied to the cochleaby the electroporation electrodes() and() during electroporation process. Merely for ease of illustration, the electroporation shield has been omitted from.

illustrate an arrangement in which the cochlear implantincludes an external component. However, it is to be appreciated that embodiments of the present invention may be implemented in cochlear implants having alternative arrangements. For example,is a functional block diagram of an exemplary totally implantable cochlear implantconfigured to implement embodiments of the present invention. Since the cochlear implantis totally implantable, all components of cochlear implantare configured to be implanted under skin/tissueof a recipient. Because all components are implantable, cochlear implantoperates, for at least a finite period of time, without the need of an external device. An external devicecan be used to, for example, charge an internal power source (battery). External devicemay be a dedicated charger or a conventional cochlear implant sound processor.

Cochlear implantincludes an implant body (main implantable component), one or more input elementsfor capturing/receiving input audio signals (e.g., one or more implantable microphonesand a wireless transceiver), an implantable coil, and an elongate intra-cochlear stimulating assembly.

The stimulating assemblyis substantially similar to stimulating assemblydescribed above with reference to. That is, stimulating assemblycomprises a carrier memberand is configured to be at least partially implanted in the recipient's cochlea. A plurality of longitudinally spaced electrodes()-() that collectively form a contact or electrode array, as well as electroporation electrodes() and(), are disposed in/on the carrier member. Lead regionincludes a plurality of conductors (wires) that electrically couple the electrodesand to the stimulator unit.

Similarly, cochlear implantalso comprises an extra-cochlear electrode(), which is substantially similar to extra-cochlear electrode() described above with reference to. That is, extra-cochlear electrode() is connected to a leadthat includes one or more conductors that electrically couple the extra-cochlear electrode() to the stimulator unit. The intra-cochlear electrodes()-() and the extra-cochlear electrode() are sometimes collectively and generally referred to herein as “stimulation electrodes.”

also illustrates that the stimulating assemblyincludes two (2) electroporation electrode contacts (electrodes)() and(). As described further below, the electroporation electrodes() and() are electrically connected to an external electroporation devicevia an electroporation lead(e.g., one or more wires). As described elsewhere herein, the electroporation electrodes() and() can be used to electroporate the recipient's cochlea nerve cells during implantation of the stimulating assemblyinto the cochlea. That is, the electroporation electrodes() and() may be configured to source, sink, or both source and sink electroporation signals (generated by external electroporation device) that result in the application of an electroporation electrical field to the nerve cells of the cochlea. Thereafter, the electroporation electrodes() and() can be electrically isolated from the external electroporation device(e.g., electrically disconnected). Although shown as two electrodes located at the distal endof the stimulating assembly, the more than two electroporation electrodes may be present and used for electroporation.

As noted elsewhere herein, electrodes configured for use in performing electroporation, such as electrodes() and(), are referred to as “electroporation electrodes.” The electroporation electrodes()/(), and the external electroporation device, are collectively referred to herein as an “electroporation sub-system”. In the embodiments of, the electroporation sub-systemis referred to as being integrated with the cochlear implant.

Electroporation electrodes() and() are structurally distinguishable from the stimulation electrodes()-() in that the electroporation electrodes are not connected to the stimulator unit, whereas the stimulation electrodes()-() must be connected to the stimulator unitto enable operation thereof. In particular, the high voltages associated with electroporation could damage the stimulator unitand, as such, the stimulation electrodes()-() cannot be used to perform electroporation. In addition, in order to perform electroporation while the stimulation electrodes()-() are implanted, the electroporation electrodes() and() must be electrically isolated from the stimulator unit. Presented herein are techniques to electrically isolate the stimulator unitfrom the electroporation electrodes() and(), and thus the high voltage electroporation signals, with an electroporation shield.

More specifically, in the example of, the electroporation electrodes() and() are used to electroporate the recipient's cochlea nerve cells during implantation of the stimulating assemblyinto the cochlea (i.e., used during application of an electroporation electrical field to the cochlea). As further described herein, the stimulating assemblymay also be equipped with an electroporation shield that serves to electrically insulate (e.g., electrically isolate or shield) the intra-cochlear electrodes()-(), and thus the stimulator unit, from the electroporation electrical field applied to the cochlea by the electroporation electrodes() and() during electroporation process. Merely for ease of illustration, the electroporation shield has been omitted from.

The microphoneand/or the implantable coilmay be positioned in, or electrically connected to, the implant body. The implant bodyfurther comprises the battery, RF interface circuitry, a processing module, and a stimulator unit(which is similar to stimulator unitof). The processing modulemay be similar to processing moduleof, and includes sound processor.

In the embodiment of, the one or more implantable microphonesare configured to receive input audio signals. The processing moduleis configured to convert received signals into stimulation control signalsfor use in stimulating a first ear of a recipient. Stated differently, sound processoris configured to convert the input audio signals into stimulation control signalsthat represent electrical stimulation for delivery to the recipient.

As noted above,illustrate an embodiment in which the external componentincludes the processing module. As such, in the illustrative arrangement of, the stimulation control signalsare provided to the implanted stimulator unitvia the RF link between the external coiland the internal coil. However, in the embodiment ofthe processing moduleis implanted in the recipient. As such, in the embodiment of, the stimulation control signalsdo not traverse the RF link, but instead are provided directly to the stimulator unit. The stimulator unitis configured to utilize the stimulation control signalsto generate electrical stimulation signals that are delivered to the recipient's cochlea via one or more stimulation channels.

As noted, the techniques presented herein may be implemented in a number of different types of tissue-stimulating prostheses and other implantable medical devices. However, merely for ease of description, further details of the techniques presented herein will generally be described with reference to cochlear implants.

illustrate example arrangements in which an “electrical electroporation shield” or “electroporation shield” is disposed around a portion of stimulating assembly of a cochlear implant such that the electroporation shield is at least partially disposed between the electroporation electrodes and the intra-cochlear electrodes of the stimulating assembly. Referring first to, shown is a simplified schematic side view of a portion of an implantable component(mainly the lead regionand intra-cochlear stimulating assembly) configured to be implanted in the cochlea of a recipient.illustrates a specific arrangement in which the stimulating assemblyof the implantable componentcomprises twenty-two (22) intra-cochlear electrodes, labeled as electrodes() through(). The intra-cochlear electrodes()-() form an electrode array.illustrates a cross-sectional view (taken along section A-A of) of the stimulating assemblyofwhere intra-cochlear electrode() is located. It is to be appreciated that embodiments presented herein may be implemented in alternative arrangements having different numbers of intra-cochlear electrodes.

As shown, intra-cochlear electrode() is the most basal/proximal intra-cochlear electrode, while intra-cochlear electrode() is the most distal/apical intra-cochlear electrode. The intra-cochlear electrodes()-() are each disposed in an electrically-insulating carrier member or bodyformed, for example, from an elastomer or other resiliently flexible material. The electrodes()-() are all connected to a stimulator unit via conductors that extend through the carrier memberof the stimulating assemblyand a lead region. For ease of illustration, the conductors and stimulator unit have all been omitted from.

also illustrates an electroporation shield or insulation sheaththat may be disposed over at least a portion of the stimulating assembly. The electroporation shieldmay include a first or proximal endand a second or distal end. The proximal endof the electroporation shield may be disposed proximate to the lead region, while the distal endof the electroporation shield is disposed more proximate to the distal/apical intra-cochlear electrode() than the proximal end. In the illustrated embodiment, the distal endof the electroporation shieldis disposed between intra-cochlear electrode() and intra-cochlear electrode(). In some embodiments, the distal endof the electroporation shieldmay be disposed proximate to the distal end (tip)of the carrier member, while in other embodiments, the distal endof the electroporation shieldmay be disposed proximate to any one of the intra-cochlear electrodes()-(). As further described below, the length of the electroporation shield(i.e., the distance between the proximal endand the distal endof the electroporation shield), and the location of the distal endof the electroporation shield, may at least partially correspond to the location of the electroporation electrodes(),(). As best illustrated in, the proximal endof the electroporation shieldmay include one or more tabs or protrusions. These tabsmay be disposed outside of the cochlea when the implantable componentis implanted in a recipient.

As best illustrated in, the electroporation shieldmay not entirely encircle the stimulating assembly. Instead, the electroporation shieldmay encircle only a large enough portion of the stimulating assemblyto cover and properly insulate the intra-cochlear electrodes, while leaving a portion of the electrically-insulating carrier member or carrier memberexposed (i.e., the portion of the carrier memberthat does not include an intra-cochlear electrode). The electroporation shieldmay be made of a thin and flexible insulating material that insulates the intra-cochlear electrodes()-() from the electrical field produced by the electroporation electrodes(),() during electroporation. Thus, the electroporation shieldmay be configured to electrically insulate the intra-cochlear electrodes()-() from voltages generated during electroporation that may reach up to approximately 150 V. The electroporation shieldmay be constructed from insulating materials such as, but not limited to, polydimethylsiloxane silicone (having the chemical compositionillustrated in), polyurethane (having the chemical compositionillustrated in), etc. Moreover, the electroporation shieldmust be thin enough to minimize any trauma that may be imparted onto the cochlea and other parts of the recipient during removal of the electroporation shield, while being thick enough to pull itself and any attached electroporation electrodes(),() with it. Thus, the electroporation shieldmay have a thickness in the range of, for example, 5-100 μm.

Returning to, electroporation electrode() may be coupled to the outer surface of the electroporation shieldand positioned proximate to intra-cochlear electrodes()-(), while electroporation electrode() may also be coupled to the outer surface of the electroporation shieldbut positioned proximate to intra-cochlear electrodes()-(). As best illustrated in, the electroporation electrode() is disposed atop the electroporation shieldsuch that the electroporation shieldis disposed between the electroporation electrode() and the intra-cochlear electrodes()-(). While not also illustrated in, electroporation electrode() is similarly disposed atop the electroporation shieldsuch that the electroporation shieldis disposed between the electroporation electrode() and the intra-cochlear electrodes()-(). In some embodiments, the electroporation electrodes(),() may be coupled to the electroporation shieldsuch that the electroporation electrodes(),() are removed from the stimulating assemblywhen the electroporation shieldis removed from the stimulating assembly. In other embodiments, the electroporation electrodes(),() may be loosely coupled to the electroporation shield, or simply placed atop the electroporation shield, such that the electroporation electrodes(),() may be removed prior to removing the electroporation shield, or vice versa. The electroporation electrode positions shown inmay be used, for example, to provide electroporation at two locations (e.g., distal and proximal) in the cochlea. The electroporation shieldmay be positioned on the stimulating assemblyas a function of the desired positions of the electroporation electrodes(),() such that the electroporation shieldcovers or insulates only the intra-cochlear electrodes()-() that may be exposed to the high voltage potentials during electroporation (i.e., intra-cochlear electrodes()-() positioned far enough away from the electroporation electrodes(),() may not need to be electrically insulated by the electroporation shield).

The electroporation electrodes(),() are connected to an external electroporation system/device (not shown). However, unlike the electrodes()-(), conductors or leads(),() extend from the electroporation electrode(),(), respectively, across the outer surface of the electroporation shieldthrough to the electroporation device. In the embodiment illustrated in, the electroporation electrode conductors(),() may be thin enough and flexible enough to minimize any trauma that may be imparted onto the cochlea during removal of the electroporation electrodes(),(), but may be thick enough to reduce the impedance of the conductors(),() below 1 kΩ. Thus, the electroporation electrode conductors(),() may have a depth and/or diameter of, for example, approximately 5-25 μm.

The stimulating assemblyand the electroporation shieldare sometimes collectively and generally referred to herein as an “electroporation shielded stimulation arrangement”. That is, as used herein, the term “electroporation shielded stimulation arrangement” refers to a structure comprising an electroporation shield coupled to, positioned over, and/or slid over a component of an implantable medical device (e.g., such as stimulating assemblyof the implantable component) such that the electroporation shield is disposed over and covers a plurality of stimulation electrodes disposed on the component, and electrically connected to, a stimulator unit of the implantable medical device. In addition, electroporation shielded stimulation arrangementpresented herein includes one or more electroporation electrodes (e.g., such as electroporation electrodes(),()) electrically connected to an electroporation device, but electrically insulated/isolated from the plurality of stimulation electrodes and stimulator unit of the implantable medical device. That is, the electroporation shield is disposed between the electroporation electrodes and the plurality of stimulation electrodes. In certain embodiments, the one or more electroporation electrodes are coupled (e.g., securely, loosely, etc.) to an outer surface of the electroporation shield that is disposed on the component of the implantable medical device.